Wear-Preventive Characteristics of a Lubricating Bio-Fluid Using a Four-Ball Method

This project studies the tribological performance of blended coconut oil as an environmentally friendly lubricant using a four-ball experiment. There has been growing concern over the use of mineral oils as lubricants in environmental issues such as soil and water pollution due to their persistence and potential to leach harmful chemicals into the environment. Several studies have been conducted on using coconut oils as alternatives to industrial gear oil; however, limited research has been conducted, especially regarding the different concentrations of blended coconut oil. Therefore, the tribological characteristics of lubricants with different ratios of Industrial Gear Oil VS 220 and coconut oil (5%, 10%, 15%, 20%, 25%, and 30%) were experimentally tested. The coefficients of friction and wear-preventive characteristics were evaluated with control based on the ASTM D4172 standard. Additionally, six (6) samples were blended using the sonication technique with the help of bench-top ultrasonic cleaner (DELTA). Hence, the result clearly indicates that 30% exhibited a lower friction coefficient (0.055) than 10%, which showed the highest value at 0.09. The surface morphology of the worn surfaces was observed using an Olympus Metallurgical Microscope. Under microscopic analysis, the 30% oil concentration yielded a smaller scar diameter than the other concentrations. As a result, increasing the mixed coconut oil concentration in the blend, specifically to 30%, resulted in a noticeable improvement in tribological performance. This included a reduction in the coefficient of friction and a decrease in the scar diameter compared with the other samples, suggesting that higher concentrations of coconut oil can enhance the lubricant’s environmental friendliness and performance in industry.